Fix UI translation partly missing in scons builds (reported by Leon Cheung and Gabriel Gazzán on ML, and lockal on IRC, thanks).

The problem is that, when HAVE__BOOL is not defined (as it is the case in scons currently), BLI_utildefines.h defines bool as a standard type. Was using signed char, which makes eg "bool foo = 1024" be false (overflow)! Especially nasty when using bitflags (think we have been lucky to not have worse bugs because of that)!

So changed fallback bool type to unsigned int.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54234 954f8c5b-7b00-dc11-b283-0030488c597c